I have a Mazda with the 2.5 Skyactiv-G.
I had some issues before at about 35k miles and had to replace both fuel pumps. I don’t have any error codes but live data shows my long term fuel trim at +20. The car seems to run fine and I don’t know enough really to know what to look for as a possible problem. I’ve ran a couple fuel injection cleaners through and it doesn’t look like it helped so far.
Thanks for your time.
Positive Long Term Fuel Trim indicates there's too much air relative to the consumed fuel in the exhaust, which Scotty describes as running lean. It means the computer is adding 20% fuel to compensate. Is your Check Engine Light on? Adding 20% is quite a bit off, and sounds to me like a vacuum leak. Look for vacuum hoses that are disconnected and reconnect them. Also, spray WD-40 or carburetor cleaner on and around hoses, manifold gaskets, etc. Spraying a vacuum leak with anything flammable will cause the idle to change, which you can hear. Do that part on a cool engine to minimize your fire risk.
